I think it is a little like asking where is 2+2... or where is math... we know that mathematical laws exist even though we can't stub our toe on one... We don't think of these laws as being changed by time or having a beginning or end... and, although we accept that they do exist, we don't think of math as having originated from any one place or time.

The Bible repeatedly says that the heavens is his dwelling place. When King Solomon gave his dedication address for the newly built temple, he used that expression many times:

1 Kings 8:41-43
41 “Also concerning the foreigner who is not part of your people Israel and who comes from a distant land because of your name*

42 (for they will hear about your great name+ and your mighty hand and your outstretched arm), and he comes and prays toward this house,

43 may you then listen from the heavens, your dwelling place, and do all that the foreigner asks of you, so that all the peoples of the earth may know your name and fear you, as your people Israel do, and may know that your name has been called on this house that I have built.

The Lord's Prayer says Our Father, who art in heaven...

Heaven is not a physical place, just like God is a spirit. John 4:24 But that is what the Bible says:

Matthew 23:22
22 and whoever swears by heaven is swearing by the throne of God and by the One sitting on it.

Acts 7:49
49 ‘The heaven is my throne and the earth is my footstool. What sort of house will you build for me? Jehovah says. Or where is my resting-place?

But he is aware of everything that goes on in the universe, and can travel anywhere that his will takes him. Which is why the scripture says:

Hebrews 4:13
13 And there is not a creation that is hidden from his sight, but all things are naked and openly exposed to the eyes of the one to whom we must give an account.

This makes sense that where he is, is a spiritual place, because when anyone prays and looks upward, God still hears them, and receives their prayer, although all of those who pray, all over the earth, are looking upward but in different directions. And he favorably answers prayers that are according to his will:

1 John 5:14
14 And this is the confidence that we have toward him, that no matter what we ask according to his will, he hears us.